In my copending application entitled, DOCKBOARD ASSEMBLY, Ser. No. 355,688, filed on Mar. 8, 1982, now U.S. Pat. No. 4,455,703 issued on June 26, 1984 an adjustable dockboard was disclosed having a tread plate movable from a storage position within a ramp to an operative position extending partly out of the ramp. The tread plate on the tread plate assembly should be in abutting engagement with the front edge of the ramp. Movement of the tread plate into engagement with the front end of the ramp was dependent upon engagement of the tread plate with the bed of the carrier. The force imposed on the tread plate was absorbed by the wheels on the rear wheel assembly on the carrier assembly. The dockboard had to be provided with mounted fixtures that correspond to those on the loading dock. The cross travel stops for the ramp were permanently mounted on the sides of the pit and the loading dock. This required each dockboard to be specially designed for mounting on each loading dock.